Process of making concentrated sulfuric acid.



0. PROELS3. PROCESS OF MAKING GONCENTRATED SULFUBIO ACID. APPLICATION FILED MAY 10, 1907. 963,174. Patented July 5, 1910.

affozma o 0. PROELSS. PBOOESS or MAKING uononmnunn SULFUBIO ACID.

APPLIGATIDH FILED MAY 10, 11107.

Patented July 5,1910.-

a sums-sum 2.

wi lmmeo AM (/3 c M OTTO PROELSS, OF KANSAS CITY, MISSOURI.

PROCESS OF MAKING GONCENTRATED SULFURIC ACID.

, Specification of Letters Patent.

Patented July 5, 1910.

Application filed May 10, 1907. Serial No. 372,980.

To all whom it may concern:

Be it known that I, Orro PROELSS, a citizen of the United States, residing at Kansas City, in the county of Jackson and State of Missouri, have invented certain new and useful Improvements in Processes of Making Concentrated Sulfuric Acid, of which the following is a specification.

Many attem ts have been made to produce sulfuric acid 0 a strength of 66 without the employment of'an undue amount of labor and material, by the use of an ordinary sulfuric acid chamber and tower plant, but such attempts, so far as I am aware, have not resulted in such a saving of either labor or material as to render the processes and means employed desirable.

I have discovered that by independently denitratin and concentrating difi'erent bodies of liquor, usingsulfurous acid gas in this connection, and thereafter bringing together the hot gases from the concentrating means, and the cooler gases from the denitrating means, and subjecting them to the action of the weak sulfuric acid, I am enabled to secure the desired result.

While different forms of apparatus may be employed for this purpose, I have illustrated oneform which has proved practicable in the: accompanying drawing, in which Figure I is an elevation of the said appa: ratus showing dia%ammatically pumps and conducting pipes; ig. 2 is a side view looking in thedirection of the arrow a, Fig. 1, and Fig. 3 is a view illustrating a modification.

In carrying out my rocess I make use of three independent an separate chambers, which may be within one or more structures or buildings, but which, as shown, are in three towers, A, A and B, each of which 7 may be a Glover tower of ordinary construction.

With the lower end of each of the towers A, A communicates a ipe or flue E, from which hot sulfurous acid gas is conducted to the tower from the burners, or roasting furnaces, etc., and from the top of each tower A A a pipe or flue V extends laterally to the tower B. From the tower B a pipe or flue 4 extendsto an exhauster F of any suitable character to convey the gases to the chambers; and suitable coolers C C,

C are arranged to receive the liquor from the bottom of each of the towers.

The tanks T, T and T are suitably connected with the towers A A and B respectively, by means of suitable distributing devices. A pump P supplied by a pipe S with chamber acid from the chambers, and by a pipe S from the cooler C delivers the liquor through the discharge pipe S and branch pipes into the tanks T and T It will benoted that the liquor in G contains nitrogen oxids in solution. The weak acid from tank T passes down the tower B and is delivered into the cooler C an overflow pipe S being provided which may lead to a storage tankor the chambers. A pipe S supplies the tank T with nitrous vitriol from the Gay Lussac tower. The liquor from tank T passes down the tower A collects in the cooler C, and is delivered by means of a pipe S to the pump P, which delivers the liquor by means of a discharge pipe S to the tank T The liquor from tank T passes down the tower A discharges into the cooler G which delivers by a pipe S to a pump P, which is connected to a discharge pipe S leading to the storage tank.

The hot gases from the tower A pass to tower B, and the cooler gases from the tower A also pass to the tower B, suitable dampers D, D regulating the flow of these gases, and as these are mixed together in the tower B, they are subjected to the action of weak sulfuric acid, which is discharged into the tower B from the tank T supplied from the lead chambers and from tank C through S as described and properly distributed in the tower.

In operating the apparatus both towers are supplied through the fiues E withthe sulfurous acid gas,- and the tower A is fed with a mixture of chamber acid and nitrous vitriol, as usual, with the result that the liquor at the bottom of the tower and carried to the cooler O is of a strength of from 60 to 62 Be. This liquor is then elevated to the top of the tower A by the pump P, the apparatus being so regulated that a concentration will be effected in the tower A .and will in all cases produce a liquor extower, of moderate temperature and laden with nitrogen compounds, and those issuing from the concentrating tower, and free from nitrogen compounds and of high temperature, are brought together inthe intermediate tower, the function of which is to unite and thoroughly mix these gases and reduce the temperature of the gases from the concentrating tower so that the mixed "gases are at a temperature which will not be injurious in the further operations. To this end these mixed gases are subjected in the intermediate tower to the action of the cool weak sulphuric acid, the operation being so regulated that the gases will issue from the intermediate tower at such temperature asiis demanded by mechanical and chemical considerations. In other words, myprocess splits the available burner gas into two parts, one part is used to denitrate the nitrous vitriol and concentrate the weak sulfuric acid formed in the chambers, and the other part of the burner gases is used to effect a further concentration of the 60 to 62- sulfuric acid thus produced. The waste gases resulting from the two parallel operations are then brought together mixed and cooled in a-subsequent intermediate tower before being admitted to a series of chambers and Gay Lussac towers.

It will be noted that due to the high concentration of the acid in the tower A the gases issuing therefrom will be very hot while the gases issuing from the tower A will not be at such a high temperature. It is for the purpose of cooling down the hot gases issuing from A that the tower B is provided, Where the hot gases from A thoroughly mix with the gases from A and the mixture is cooled to a low temperature, due to the excess of acid percolating down B. It is much easier to construct the lining of A so as to resist the high temperature and the strong acid than it is to construct the entire lining of the chambers which are of very large area, and therefore the lining in Y A is a special acid and heat resisting lining,

greater amount of fuel, labor or supervision than is ordinarily required in producing acid of much lower strength, and by means of properly constructed flues and dust cham bers the acid may be had of the proper light color, or freedom from color.

It will be evident that while in .Figs. 1 and 2 I have shown three structures in order to provide the proper independent chambers, it is wholly immaterial whether such chambers be in a plurality of structures or not. In the construction shown in Fig. '3 the tower B corresponds to the tower B of Figs.

1 and 2, but the tower A is subdivided ver-' tically into two chambers.

Without limiting myself to the details of operation or apparatus hereinbefore set forth, I claim as my invention:

1. The method of manufacturing concentrated sulfuric acid which consists in independently operating upon two bodies of liquor to denitrate one and concentrate the other in the presence of hot sulfurous acid gas, and then bringing the gases from the two operations together into contact with cool weak acid before discharging them into the chambers.

2. The method of manufacturing concentrated sulfuricacid which consists m exposing independent portions of the liquor to the action of the hot burner gases one for denitration and the other for concentration, and thereafter bringing the gases together into contact with weak liquor before discharging them into the chambers.

3. The method of manufacturing concentrated sulfuric acid which consists in exposing independent portions of the liquor to the action of the hot burner gases one for denitration and the other for concentration, and thereafter bringing the gases together into contact with an excess of weak cool liquor before discharging them into the chambers.

4. The method of manufacturing concentrated sulfuric acid which consists in conducting independent portions of the hot burner gases through a denitrating apparatus and a concentrating apparatus, and thereafter bringing the gases-together into a cooling apparatus before discharging them into the chambers.

5. The method of manufacturing concentrated sulfuric acid which consists in conducting independent portions of the hot burner gases through a denitrating apparatus and a concentrating apparatus, and thereafter brin ing the gases together and passing them t rough a cooling apparatus into contact with an excess of dilute liquor before discharging them into the chambers.

6. The method of manufacturing concentrated sulfuric acid which consists in conducting independent portions of the hot burner gases through a denitrating apparatus and a concentrating apparatus, thereafter bringing the ases together into a cooling apparatus in tile presence of weak liquor before discharging them into the cham- 5 bers, and discharging the denitrated liquor from the denitrating apparatus into the concentrating apparatus.

7. The method of manufacturing concentratedsulfuric acid'which consists in con- 10 ducting independent portions of the hot burner gases through a denitrating apparatus and a concentrating apparatus, and

thereafter bringing the gases together and passing them t ough a coolin apparatus mto contact with an excess of ilute liquor 15 before discharging them into the'chambers, and using the dilute liquor from the cooling apparatus in the denitratin apparatus.

In testimon whereof I a x my signature in presence .0 two witnesses.

' OTTO PROELSS. .Wit'nesses: C. M. BULKLEY,

J. P. MITSAY. 

